In various data transmission systems, data is transmitted by means of an optical signal over an optical path or optical channel. In a receiver of such a communication system, the optical signal may be transformed to an electrical signal, which may be digitally sampled for further processing.
However, the optical path or optical channel may comprise channel imperfections, such that the received optical signal comprises distortions introduced by the optical path. One of such possible distortions is a chromatic dispersion, according to which different wavelengths of the optical signal are transported with different velocities within an optical medium of the optical path or the optical channel, resulting, for example, in broadened pulses of the received optical signal. To compensate for such distortions, the received signal may be accordingly processed to revert the effects of a certain chromatic dispersion of the optical medium. However, the chromatic dispersion of the optical medium may not be known in advance such that an estimation of the certain chromatic dispersion may be necessary.
Various estimation techniques for estimating a chromatic dispersion may be deployed. For example, an averaging auto-correlation function of the receive signal in the frequency domain may be applied. Furthermore, a mean square error of a compensated signal may be evaluated to find a certain chromatic dispersion. However, such estimation techniques may show a degraded performance regarding polarisation rotation or differential group delay.